Plextek Limited

Redtail Telematics Limited

Peter Massam

Timothy David Howe

Philip Alan Bowden

Timothy Jackson

Kevin Jones

Peter Debenham

Tony Allen

A method, system and computer program for determining the orientation of an apparatus relative to a vehicle in which the apparatus is installed is disclosed. Acceleration data of the apparatus along three mutually orthogonal axes at a first time interval is recorded (). Speed and heading data of the apparatus at a second time interval is recorded (). A first vector which corresponds to the direction of gravity is determined () using the acceleration data. One or more periods of acceleration in a substantially straight line are identified () using the speed and heading data. Acceleration data corresponding to the identified one or more periods of acceleration in a substantially straight line is selected (). A second vector which is orthogonal to the first vector and which corresponds to a forward direction of the vehicle is determined () using the selected acceleration data.

Method, system and computer program for determining the orientation of an apparatus

An RF receiver comprises a signal processor arranged to perform a method of decoding data contained within a signal that comprises a set of slots, at least one said slot comprising a preamble portion and a payload portion and being transmitted at a predetermined transmission frequency. The signal processor is arranged to perform a first process to derive timing data from the preamble portion and perform a second process to extract information from the payload portion, the second process being triggered from said timing data derived from the first process. The preamble portion comprises at least a first sequence of data and a second sequence of data, and the second sequence is the inverse of the first sequence. In preferred embodiments the first process comprises identifying a transition between said first and second sequences of data and deriving said timing data from the identified transition.

Narrow band receiver

The data transmitted from a first station is transmitted at a first data rate. The data transmitted from a second station is transmitted at a second data rate. The second data rate is lower than the first data rate. In view of both the difference in data rates and the synchronization between radio stations, a separate synchronization word is not required to be sent from the second station to the first station on the uplink portion; instead, and because the uplink slots of a given frame are synchronized between transceiving stations, the start of the uplink payload slot can comprise signalling information which simply acts to signify the start of transmission of uplink data from the second station.

Narrow band transceiver

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Saffron Walden, United Kingdom

Peter Massam